Perform storage operations for GUI and CLI via management service (and remove the Jetty frontend) about knix

[iakkus]

As the HttpFrontend component is getting removed, we'd also need to move the HttpFrontend/nginx_config/ somewhere else and update the relevant ansible/helm files.

Update: The nginx config template has been moved to deploy/ansible in the 'develop' branch, so it is safe to remove here.

[iakkus]

@paarijaat do you have a branch for this?

[iakkus]

Branch feature/storage_ops_via_management_remove_httpfrontend.

[iakkus]

So far, we had always allowed access to the KV store in the GUI. Do you think we should also supply the functions to access the rest of the data structures (i.e., maps, sets, counters) @paarijaat @abeckn?

(I guess after the issue related to the storage triggers (#31), we can also add those as well, but those should be handled perhaps from that branch and not this one.)

By the way, do we envision a single function with different parameters (e.g., "op"="getMap", params={"name": mapname, "is_private": true}, "op"="getSet", params={"name": setname, "is_private": false})? Or do we envision a separate function for each operation?

I think a single function would suffice; otherwise, there would be 30+ functions just for storage access, which might a bit inefficient, assuming the access to such data is not really the most frequent ones (compared to other management actions).